“脏读”在设置为未提交隔离级别的事务范围内不工作

Question

我有一个类似这样的代码：

using (TransactionScope scope = 
   new TransactionScope(TransactionScopeOption.Required), new TransactionOptions)
{ 

    IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted }))
    // "dirty" read  for test purposes , to see if my 
    // select will actually select the information I just inserted

    actual = target.GetCostCentersRates(accountId);

}

这不起作用，我已经测试了查询，它们在提交数据时有效地工作，但是当未提交数据时，它会出现不允许我脏读的问题check ，即使隔离级别设置为 readuncommited 也是如此。 我想弄清楚为什么我无法访问这些信息，因为我无论如何都无法将信息提交到我们的数据库中，因为这是一种测试方法。
谢谢！

这是整个事情的经过

 public void GetCostCentersRatesTest()
    {

        using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, new TransactionOptions { IsolationLevel = System.Transactions.IsolationLevel.ReadUncommited }))
        {
            //Arrange
            BRL.AdministrativeArea.SystemClientBusinessRole systemClient = new BRL.AdministrativeArea.SystemClientBusinessRole();
            int systemClientId = systemClient.InsertSystemClient(systemClientInfo).systemClientId;
            BRL.BRLProperties.systemClientId = systemClientId;
            employeeInfo.multiCompaniesInfo.systemClientId = systemClientId;
            int stateId = 1;
            int cityId = 1;
            int functionId = 1;
            employeeInfo.stateId = stateId;
            employeeInfo.cityId = cityId;
            employeeInfo.functionId = functionId;
            int employeeId = employees.InsertEmployeers(employeeInfo);
            BRL.BRLProperties.employeeId = employeeId;
            IActionReturnInfo actionAccount = (accounts.InsertAccountPlan(accountPlanInfo));
            int accountId = Convert.ToInt32(actionAccount.UpdateDataSourceList[0].ToString());
            clientInfo.stateId = stateId;
            clientInfo.cityId = cityId;
            clientInfo.stateIdCorrespondency = stateId;
            clientInfo.cityIdCorrespondency = cityId;
            clientInfo.stateIdDelivery = stateId;
            clientInfo.cityIdDelivery = cityId;
            clientInfo.multiCompaniesInfo.systemClientId = systemClientId;
            clientInfo.multiCompaniesInfo.employeeId = employeeId;
            int clientId;
            clients.InsertClient(clientInfo, out clientId);
            centerCostInfo.systemClientId = systemClientId;
            centerCostInfo.clientId = clientId;
            centerCostInfo.employeeId = employeeId;
            centerCostInfo.directorID = employeeId;
            centerCostInfo.managerID = employeeId;
            centerCostInfo.multiCompaniesInfo.systemClientId = systemClientId;
            centerCostInfo.multiCompaniesInfo.employeeId = employeeId;
            IActionReturnInfo action = new CenterCostsBusinessRole().InsertCostCenter(centerCostInfo);
            int centerCostId = Convert.ToInt32(action.UpdateDataSourceList[0].ToString());
            rate.accountId = accountId;
            rate.centerCostId = centerCostId;
            costCenterRates.Add(rate);
            int costCenterRateId;
            AccountBusinessRole target = new AccountBusinessRole();
            DataSet actual;

             IActionReturnInfo costCenterRateAction = accounts.InsertCenterCostRates(costCenterRates);
                costCenterRateId = Convert.ToInt32(costCenterRateAction.UpdateDataSourceList[0].ToString());

                //Act
                actual = target.GetCostCentersRates(accountId);



            //Assert
            Assert.IsTrue(FindInDataset(costCenterRateId, actual, "ACCOUNTID"));
        }
    }

......

Answer 1

让脏读发挥作用。
您（明确）开始交易
将更改推送到数据库

在另一个事务中，未提交
选择数据，您也会得到未提交的内容。

然后，您可以回滚或提交您进行更改的事务。

因此，从 sql server manager 来看
启动一个查询

Start Transaction
Insert SomeTable(500)

启动另一个查询，

Select * from SomeTable With(READUNCOMMITTED)

您将看到 500 条记录。

老实说，试图弄清楚为什么要这样做，ADO.Net 使用的断开连接模型使得除了分布式事务之外没有必要这样做，并且您不会像这样测试它们。如果您要测试的只是插入，那么就这样做，听起来几乎就像您在实时数据库上进行测试一样，这是一件非常糟糕的事情。